Liquid level control for volatile liquids



Dec. 4, 195] T. J. PEUKERT 2,577,358

LIQUID LEVEL CONTROL FOR VOLATILE LIQUIDS Filed Sept. 15, 1947 sSheets-Sheet 1 IN VEN TOR. THEODORE J. PE UK E E T Dec. 4, 1951 T.JFPEUKERVT 2,577,358

LIQUID LEVEL CONTROL FOR VOLATILE LIQUIDS Filed Sept. 15, 1947 5sheets-sheet 2 Fig. 4.

IN VEN TOR. THEODORE d PEUKEE T Dec. 4, 1951 PEUKERT 2,577,358

LIQUID LEVEL CONTROL FOR VOLATILE LIQUIDS Filed Sept. 15, 1 947INVENTOR. THEODORE J. PEU/(EPT BY 6474 W I5 Sheets-Sheet 3- PatentedDec. 4, 1951 Theodo J- Pfl I168 An e s. Ca m;

ppueatmri'se teihber 15, 1947', Serial No. 774,041

h Thisinvention relates to" liquid level controls foi controllingthedepth of volatile-liquidcori tained in a system for utilizing suchliquid and moreparticularly to remote controls for controlling liquidlevels of refrigerantliquidsexisting refrigerating systems.- neimportant object of the present inventionis to provide a remotecontrol'for the level of a liquidina container whereinthe vaporizationorthe liquid itself is utilized for cuttingioff-the su'pply'of liquid tothe container-when the con-- tamed liquidis at its desired limitinglevel.

Another object of the inventionis to provide a -controlling system forthis purpose wherein the system is fully automatic and requires nosupervision or adjustment while in use.

Another feature of the invention is the pro vision of a liquid levelcontrolw herei n*-the controlled-liquid level can be easily and readilychanged or adjusted so" as to carry the operating level of the liquid atany desired heightwithin' the-rangeof the system.

A-iurther object ofthe invention is to provide amovelliquid levelcontrol which operates under static conditions of liquid to controlthelevelthereof without the use of any moving-mechanism immersed in theliquid or inaccessible within the centainerho'lding-the liquid. I v

still further object of the invention is topr'o'videja' liquidlevelcontrol reinote from the vesselin which is-contained the liquidthe-level cfi which is t'obe controlled whereby; -for instance, inarefrigerating system the container holding such: liquid may be locateda cold or ireezing' temperature while the controlling mechanism it'-self may be located ina warm and easily accessible position. I h

With-the: above and other objects" view as will be hereinafter apparent,the invention consists ingeneral of certain novel details of constructionand combinations of parts presently to be fully described,illustrated in theaccom panning-drawings and particularly claimed-i Inthe accompanying drawings like characters; parts in the severe-r 0!?reference indicate" likeviews;. and: V

.Fig-u're lie a semi-diagrammatic view of a refrigerating! plant havinga liquid: level control tcr -the-level-of theliquidin an evaporatorchanf bertthecontrol embodying theprinciples of the" presentinventionandutilizing volume' chambers;

Figure-2is' a detail section through the evapo rator used: in therefrigeration system and showing' a:- certain vapor pressure tube};cor-me'cteri thereto;

'7 Figure 3 is 'a detail elevation of one of the le-e mentsof thecontrol and showing its mounting bracket; H v o I z. --Fig-ure 4 is aview similar to Figure 1 but show-J ing a form of control without theuse ofvolume chambers. 7 Figure 5 is an enlarged elevation, partlyinsection,-

showing the liquid level control assembly; 1

Figure 6 is an enlarged detail section showing a certain ball checkusedin connection'with the apparatus of this invention. L

In theembodiments of the invention as herein shown there-is disclosedanengine driveitcoin- I pressor I0 from-which a pipeline l I extends: to

the intake smear-a condenser l2. Front this condenser a pipe [3 extendsto areceiver 14 and from this receiver a pipe line l5 leads" to anevaporator I6; which is in turn} connected to the'cornpressor I0 by apipe'Fi. This" is" substantially the usual type of refrigeration system;In the pipe line Hi there is provided a main shut off v or king valve I8which is located adjacent the" receiver [4 and further along in this'line there are arranged an expansion valve l-9-,1'a"- strainer orfilter 2'0 and a stop valve 2 I.

Likewise, in each of the formsshown there is located between thestrainer" 20 and valve 21 a: valve 22 the opening and: closing ofwhich-- iscontrolled by a solenoid 23. This solenoidrezceiveselectriccurrent from conductors '24 arid 25 and inthe latter is locateda standard io'rnr of liquid level controlled electric switch 26-"thedetailsfof which are not deemed necessaryhereto be shown V I V Theswitch 26 forms part of the control assembly' and in the form of theinvention shown Figure; 1' and 5"the lower end of the switch isconnected by a pipe 27 to the bottom 'endfo a': volume cheniber 2,81 Thepipe-2121s provided one or more union connections 29 for convenience inassembling and dis as'sembling and is-al'so pro vided with aremovable'plug. 30 in the control" assemblyg The top of the volume chamber 281s"connected to the bottom of the evaporator'b a P113164 3-! h ng were a v3 the he ep fled with union cq inec ions as at" 13 voluxne chamber hasiri its top a remova filler I plug- 3 3s that necessary non-evaporablefiuidjat' at its lower end. In the upper part of the pipe 35 there isfitted a filler plug 31 and in the U-bend there is provided a draw-oilplug 38. At 39 is a second volume chamber which is considerably shorterthan the volume chamber 28. The tops of the two volume chambers are on alevel and because of its shortness the bottom of the chamber 39 iselevated above the bottom of chamber 28. The chamber39 has a pipe 40extending from its upper end laterally and'downwardly so that'its end isvertically alined above the end of the U-bend 36. A gage glas 4| isguarded by suitable guard wires 42 and is held between the pipes Agraduated sca1e; f;'*

-' 1 liquid in volume chamber 28 to fall, and the level 35 and 40 toconnect the same. 43 is supported from the pipes 35 and 40 and U-bend 36t lie alongside of the gage glass. A pipe 44 connects the upper. end ofthe chamber 39 with the top portion of the evaporator l6 and has theusual stop valves 45 and union connection 46. A pipe 47 and union 48connect the lower end of the chamber 39. and the switch 26- somewhatabove the bottom of the latter. The latter ally extending portions ofthe pipes 35 and are connected by a by-pass pipe 49 having a stop orequalizing valve 50 therein.

In the form of the invention shown in Figure 4. the. volume chambers arenot shown, the chamber 28 being replaced by a pipe 5| and the chamber 39by a pipe 52. Otherwise the arrangements of piping and other parts i thesame as that described in connection with the volume chambers. It is tobe understood that in use volume chamber 28 (or pipe 5|) is partlyfilled with oil or other non-evaporable medium. This oil flows into pipe21 and, when equalizing valve 50 is open, comes to a desired commonlevel in chamber 23 and pipe 21. Likewise, oil is placed in pipe 35 andflows into U-bend 36 coming to a new common level in the two legs ofU-bend 36 of the liquid level gage. The desired liquid level in volumechamberZB need not be the same as in U-bend 36. Each is filled to thelevel required to give the desired operating result.

i In order to understandthe operation of this apparatus let it beassumed that it is desired to maintain the liquid content of theevaporator I6 at a height A, as seen in Figure 2. The temperature of theevaporating liquid inthe evaporator is controlled by the reduction ofpressure in the upper and gas filled portion of the evaporator throughthe evacuation of the gas by the com pressor II]. This temperature atthe evaporator is normally lower than at any other point in arefrigerating system of the type shown. The temperature in the pipe 3|,extending as it does away fromthe refrigerating system proper, isnormally higher than the temperature of the evaporator. With thearrangement as shown in Figure 2 it will be plain that a small quantityof liquidrefrigerant will be exposed to evaporation in the'conduit 3|.Since the pipe 3| opens into such gascan escape only through theevaporator as indicated by the bubbles in Figure ,2. In order to effectescape of the gas in this manner it must build up a pressure in the pipe3| greater than that existing in the evaporator, this increase in 4 ofthe liquid therefrom. However, through the connection of the pipe 21with the lower nonevaporable fluid containing part of the float switch26, a static head A as shown in Figure 5 will be effected. It is here tobe noted that the pipe 44 connects the top of the evaporator with thechamber 39 or pipe 52 and thus with the upper part of the float switch26 so that pressure on the surface ofthe non-evaporable fluid in thefloat chamber will be equal to that in the upper part (gaseous pressure)in the evaporator |6.

- Ihe static head created by the evaporating liquid in float chamber 26.to rise, resulting in a pneumane-hydraulic pressure change to raise orlower -the floatas the liquid level varies in the refrigerant chamber.Valves 53, are not necessary to the functioning of the assembly, butwhen closed permit theassembly to be worked upon or removed.

If theliquid level in the evaporator l5 rises there will be an increaseof pressure in the pipe 3| and consequently in the chamber 28. This willdepress the liquid level in chamber 28 and raise the liquid level in thefloat chamber of switch 26, thus efiecting opening of the switch andconsequent de-energization of the solenoid 23 and closing of thevalve 22so as to shut off the supply of refrigerant to the evaporator. With thes pply shut off the level of liquid in the evaporator will lower and thefloat switch will act to close the circuit. and cause energization ofthesole:

noid, putting valve 22 again in the openposition; to permit furthersupply of refrigerant to the evaporator. s v

In the same manner the level of the oil or other liquid medium in theriser 35will'be depressed and that in the gage glass will rise toestablish the equivalent head A V If the quantity of oil or other fluidmedium in the volume chamber 28 is increased then a lesser static headwill be required to bring the levelof the oil, or other medium, inchamber 26;to the height required to raise the float and operate andopen the float switch, and the level of the that in the volume chamber28 or pipe 5|.

Furthermore, the extent to which the fluid.

medium rises in the gage glass being equal to the extent to which thefluid medium rises inthe float valve, the gage glass, can be used tocheck and determine changes in and regulate the height of liquid in theevaporator,

At the points indicated by the reference char acter a ;on Figure 5 of.the drawings, check valves 65, suchas are shown .in Figure 6, are usedat the connection piping between the .s'ystemin pressure being directlyequal to the static head 7 be and this willtendto effect discharge ofsome;

which the liquid level is being controlled andthe liquid level itself.The check' valves are so set.

and connected that, upon breakage of th'e'glass,

ball 66 of the check' valve will roll-into position and automaticallyclosethe valve and prevent the escape of refrigerant from the system.

Normally, gas travel through the check valve 65 is slow and has noeffect on. the ball 66 of the check. If the gage glass 4| should be brolen-,i;

v thetenill be; thread: he. eheelsrelxe A512 to the respective rol mepassage d hat th pi es e}. to; e a ti ul rly no t v i:

- H m in r A f erelipendedst e termsfvolun e aha l l reie to be readies.to Qo erthe pipes also. 7 e

u d stan e-i onc ad her-e eerati snieansn ope a so i -s n hat. the s men of the ei zi trolv ss mbl oieeneral rshan chamber onelegtebamh r 31.and loet chamber or ing, he otherleg the ipe lio theseonpeo on betwe nthe le s. The ease. ar+- cemen s; a form of U-shaned m nometer ipe. eons ee in pzn lleltothe contro assemb er pr 7 v tn above i d level con osfor on i ne of stra i p. shown s using the le .v type a heat o rated wtch ut. ha ts use is. not co ned. to swit h, with its e ect ca reuit soe 011d a r -v ca o er ted rrangem t with, m ch nical. ink e toi he seant: on o val a arrangement using air pressure giving pneumaticecnneetiqnh iw en the eet an he va ve. o ny onv n n arr n ment, ay be ue netisdaimedis: V

as or cont o ng; thee e of a volat le am r for g-pert o a ci cula orincludi a pesu p yin fl idto.

s ve e l and.

said, ham er a d. alve co tr l ng. aid. ipe,

3 bst ntial -sha e n rollin s stem, h il-.- ones e condu c n ect d by aasfi ed con.- d t theh tom o sa d ham e and. t other ca onduit o c d.by: a g s. ll d conduit to. th to ai c amb said la t l i c udin a fle-sa legs, av n a l u re r transmi m m. n. the r Jo d we pa ts and. conto ed bys oa and ine u i aoper-+ meansior se dvalvejdgle'vel ntro for anpqieiflr-oi.

r" crat ng apparatus including a piperhaving a lyeand supplying finid tosaid evaporat fgoi ligni d in afchamber form'ingpart of a circulatorysystem and including a pipe supplying-fluid to, said chamber and a valvecontrolling said-pipe, asubsta-ntially .U -shaped controlling systemhav! ing vone: ga filled leg conduit, connectedto the; bot cm orsaideh'amherandits othereleg. conduit I t to he, und rstood, that he aplioatio i.ptv

jfn for controlling the ljevel or a, volatile acted to; the, topoiasaid: hamber. said; last: a

a. substant a ly U-shep d contr ng ystem hayinc ,9 eases. filled conduiteon otedcto the. hettonrof sai ohemberend its other. leg: es led conduitconnected o. hetop of said hamben, Said last le ncludi g a, float. saidlegs. havin a qu d pressure; transmittin .e dium t eir joinedlower-parteand ncluding operatin means. i onnectin aid floatend said alv m ans tosupp y-add tion l? med umv to and draw on. Incdium from said legs, andin combination. a Ll-shaped manometerconnected inparallel to the up rends of-sa d e s.

v5. ,1 -liqu id level control for; an evaporator of a refr eratinapparatus in lud ng a p pe: havin evolve n s pp y fluid to, aidvaporator. of e ns connec o. said v l e-f oper t he s m a. s bstantial yr haped. c ntrolling ystem h v nea l qu d pr ss r ansm t ng. m diumainthe ower parts, a d conn c i n of itslegs, one; of said legs; having; agas, filled; pipeconnection to the bottom of the ev p rator. and ormin atr p r iqu d. ref rant adj cent the. evap ra the oth r of s id e havinga as filledp -pe c nn ct on to thetop or said evaporatory and ncl d naflo t ontrolling said valve peratin me n means o supplydditional;-

medium to and draw ofimedium from said legs. and: n omb at o a p .dmanometer con nest d parallel; to the upp r en s oi Said l s.

6. A liquid level, control for an evaporator of av refrigeratingapparatlm including a pipe having a, solenoid valve; and supplyingfluidto said evaporator; a vertically elongated Volume chamber, a. gasfilled pipe leading from the bottom ofysaid, evaporator to the upperend. of said chambe'na secondvertically elongated volume chamber, a gasfilled pipe leading from the top of saidevaporator to theupper end ofthesecond chamber, a float.

chamberhaving afloattherein, a pipe connecting the, lower end of saidsecond chamber with the upper part ofthe float chamber, a pipe connectmgthe lower ends of said first and float, chambers,xsaid last mentioned"pipe and the lower parts of its connected chamber being provided withpressure transmitting liquid, and electrical con necting means fromsaid'float for controlling said solenoid'valve.

7-. A liquid level control for an evaporator of a refrigeratingapparatus including a pipe having a valve and supplyingfluid to saidevaporator, a vertically elongated volume chamber, a gasfilled pipeleadingfrom the bottom of said evaporator to the-upper end of saidchamber, a second vertically-elongated volume chamber, a gas filled pipeleading from the top of said evaporator to the} upper end of the-secondchamber, a float chamberhaving a float therein, a'pipe connecting thelow'er end of said second chamberwith the upper part ofthefioat-chamber, a pipe connecting the lower ends of "said first andfloat chambers, said last mentioned pipe and the lower parts of itsconnectedichamber being provided with pressuret'ransmitting-liquid, andelectrical means operated byithefloatfor controlling sai'd valve;

1 -8.'A liquid level control for an evaporator of a refrigeratingapparatus including a pipe having a valve and supplying fluid to saidevaporator, a vertically elongated volume chamber, a-gas filled pipeleading from the bottom of said evaporator to the upper end of saidchamber, a second vertically elongated volume chamber, a gas filled pipeleading from the top of said evaporator to the upper end of the secondchamber, a float in-a float chamber controlling an electric circuitcloser,-a pipe connecting the lower=end of said second chamber with theupper part of the float chamber, a pipe connecting the lower ends ofsaid first and float chambers, said last mentioned pipe and the lowerparts of its connected chamber being provided with pressure transmittingliquid, electro-magnetic means in circuit with said circuit closer andcontrolling said valve, and in combination a U-shaped manometer havingthe up-' per ends of its legs connected to the upper ends of said volumechambers.

9. A liquid level control for an evaporator of a refrigerating apparatusincluding a pipe having a valve' and supplying fluid to said evaporator,a vertically elongated volume chamber, a gas filled pipe leading fromthe bottom of said evaporator to the upper end of said chamber, a secondvertically elongated volume chamber, a gas filled pipe leading from thetop of said evaporator to the upper end of the second chamber, a floatchamber, a float'therein, an electric circuit closer operated by thefloat, a pipe connecting the lower end of said second chamber with theupper part of the float chamber, a pipe connecting the lower ends ofsaidflrst and float chambers, said last men-1 tioned pipe and the lowerparts of its connected chamber being provided with pressure transmit--ting liquid, electro-magnetic means in circuit with said circuit closerand controlling said valve, and in combination a U-shaped manometerhaving the upper ends of its legs connected to the upper ends of saidvolume chambers. 1

10. A liquid level control for an evaporator of a refrigeratingapparatus including a pipe having-- a valve and supplying fluid to saidevaporator, a: vertically elongated volume chamber, a gas filled pipeleading from the bottom of said evaporator to the upper end of saidchamber, a second vertically elongated volume chamber, a gas filledpipe.

leading. from the top of said evaporator to the up part of the floatchamber, a pipe connecting the.

lower ends of said first and float chambers, Said? last mentioned pipeand the lower parts of its;

connected chamber being provided with pressuretransmitting liquid, asolenoid in circuit with said circuitcloser, and a core for saidsolenoid connected to said valve and acting to open the valve uponenergization of the solenoid.

11. A liquid level control mean in combinationwith the evaporator of arefrigerating apparatus, including a pipe supplying refrigerant liquidto. said evaporator and a valve controlling flow of refrigerant liquidin said pipe; electricoperating means for said valve, a substantiallyvU-shaped' controlling tube system having the upper end of one legconnected by gas filled conduit to the lower part of said evaporatorbelow the liquid level desired to be held in said evaporator and theupper end of the other leg connected by gas filled conduit to saidevaporator above the liquid level desired to be held in said evaporator;the lower.

portions of the legs of said substantially U-siiapd tube containingfluid, the level of the surfacesof said fluid inthe two legs beingresponsive t the varying difference in pressure in the gas filledconduits connecting said legs to said evaporator, rising or falling inone leg as it falls or rises in the other and electrical contact'ormeans controlled by the rise or fall of the liquid in one of said legsto operate said valve controlling the supply of refrigerant liquid t theevaporator.

12. A liquid level control means in combination with the evaporator of arefrigerating apparatus,

including a pipe supplying refrigerant liquid to said evaporator and a'valve' controlling flow of refrigerant liquid in-said pipe; asubstantially U-shaped controlling system having the upper end of oneleg connected by gas filled conduit to the lower part of said evaporatorbelow the liquid level desired to be held in said evaporator and theupper end of the other leg connected by gas filled conduit to saidevaporator above the liquid level desired to be held'in said evaporator;the lower portions of the legs of said substantially U'shaped tubecontaining fluid, the level of the surfaces of said fluid in the twolegs being responsive to the varying difference in pressure in the gasfilled conduits connecting said legs to said evaporator, rising orfalling in one leg as it falls or rises in the other and float operatedelectrical contacting means controlled by the rise or fall of the liquidin one of said legs to operate said valve controlling the supply ofrefrigerant liquid to the evaporator. f

' 13. A liquid level control means in combination with a chamber forminga part of a circulatory system of a refrigerating apparatus, including apipe supplying refrigerant liquid to said chamber and a valvecontrolling flow of refrigerant liquid in said pipe; electric operatingmeans for said valve, a substantially U-shaped controlling system havingthe upper end of one leg connected by gas filled conduit to the lowerpart of said chamber below the liquid level desired to be held in saidchamber and the upper end of the other r leg connected by gas filledconduit to said chamber above the liquid level desired to bejheld insaid chamber; the lower portions of the" legs of said substantiallyU-shaped tube containing fluid, the level of the surfaces of said fluidin the two legs being responsive to the varying difier'ence incontrolling the supply of refrigerant liquid tothe chamber. I,

14. A liquid level control means in combination with a chamber forming apart of a circulatory system of a refrigerating apparatus, including apipe supplying refrigerant liquid to said chamber and a valvecontrolling flow of refrigerant liquid in said pipe; a substantiallyU-shaped controlling.

system having the upper end of one leg connected by gas filled conduitto the lower part of said chamber below the liquid level desired to beheld in said chamber and the upper end of the other leg connected by gasfilled conduit to said chamber above the liquid level desired to be heldin i said chamber; the lower portions of the legsof said substantiallyU-shaped'tube containing fluid,

the level of the surfaces of said fluid in the two legs being responsiveto the varying difference in y pressure in the gas filled conduitsconnecting said 75 legs to said chamber, rising or-falling in one leg asit falls or rises in the other and float operated REFERENCES CITEDelectrical contacting means controlled by the rise The followingreferences are of record in or fall of the liquid in one of said legs tooperate me of this patent: said valve controlling the supply ofrefrigeran liquid to the chamber. 5 UNITED STATES PATENTS 15. A liquidlevel control means according to Number Name Date claim 14 having meansfor operating said valve 1,805,901 Bergdoll May 19, 1931 to completelyshut oil flow therethrough and 1,838,165 Vollmann Dec. 29, 1931 whereinsaid valve constitutes the sole means of 1,862,657 Breidenthal June 14,1932 communication between the portions of the pipe 10 2,266,069Phillips Dec. 16, 1941 on opposite sides of the valve. 2,298,924Bichowsky Oct. 13, 1942 THEODORE J. PEUKERT. 2,344,245 Grossman Mar. 14,1944

